Thyrotrophin and Prolactin Response to β-(Pyrazolyl-1)-Alanine-2-TRH in Normal Males

: Synthetic beta-(pyrazolyl-1)-alanine-2-TRH, an analog of thyrotropin releasing hormone (TRH) was administered intravenously in doses of 50, 100 and 200 micrograms to four normal men in order to establish the range of responses of TSH and prolactin. Every subject showed a clear elevation in TSH and prolactin levels with all three doses. These results were compared with the increments in TSH and prolactin after the administration of the same doses of synthetic TRH. The computations of potency for absolute levels and/or increments in TSH and prolactin at 20 and 40 min showed that the analog was at least twice as active as TRH in releasing TSH and prolactin.